The present invention generally relates to material displacement apparatus and, in a preferred embodiment thereof, more particularly relates to apparatus for releasably coupling a replaceable excavating tooth point or other wear member to an associated adapter nose structure.
A variety of types of material displacement apparatus are provided with replaceable wear portions that are removably carried by larger base structures and come into abrasive, wearing contact with the material being displaced. For example, excavating tooth assemblies provided on digging equipment such as excavating buckets or the like typically comprise a relatively massive adapter portion which is suitably anchored to the forward bucket lip and has a reduced cross-section, forwardly projecting nose portion, and a replaceable tooth point having formed through a rear end thereof a pocket opening that releasably receives the adapter nose. To captively retain the point on the adapter nose, generally aligned transverse openings are formed through these interchangeable elements adjacent the rear end of the point, and a suitable connector structure is driven into and forcibly retained within the aligned openings to releasably anchor the replaceable tooth point on its associated adapter nose portion.
The connector structure typically has to be forcibly driven into the aligned tooth point and adapter nose openings using, for example, a sledge hammer. Subsequently, the inserted connector structure has to be forcibly pounded out of the point and nose openings to permit the worn point to be removed from the adapter nose and replaced. This conventional need to pound in and later pound out the connector structure can easily give rise to a safety hazard for the installing and removing personnel.
A need accordingly exists for an improved connector structure that eliminates or at least substantially reduces this problem typically associated with conventional pound-in type connectors used to releasably retain a replaceable tooth point on an adapter nose. It is to this need that the present invention is directed.
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, improved connector apparatus is provided for captively retaining an excavating wear member, such as a replaceable excavating tooth point, on an adapter nose. The adapter nose is complementarily and removably receivable in a socket portion of the wear member in a manner substantially aligning connection openings extending through the wear member and adapter nose.
The connector apparatus is representatively a connector pin assembly comprising first and second connector body members, and cooperatively engageable threaded structures operative to forcibly move the first and second connector body members toward one another in a first direction parallel to the longitudinal axis of the connector pin assembly. A resilient structure is interposable between the first and second connector body members and is operative to be resiliently compressed thereby in the first direction in response to forcible movement of the first and second connector body members toward one another in the first direction by operation of the threaded structures.
The threaded structures, although they may be separate from the connector bodies, are preferably formed integrally therewith. Representatively, the connector bodies have cylindrical shapes and the threaded structures include a reduced diameter externally threaded portion of the first connector body axially projecting from one of its ends, and an internally threaded axial end opening formed in the second connector body and into which the reduced diameter projection on the first connector may be threaded.
In a first illustrated embodiment of the connector pin assembly, the resilient structure has a tubular shape, circumscribes the reduced diameter externally threaded first connector body projection, has opposite ends that face annular inner end surfaces on the first and second connector body portions, and is of an elastomeric material. Illustratively, annular flat washers are interposed between the tubular member ends and these annular inner end surfaces. When the first and second connector bodies are threadingly advanced axially toward one another, the tubular resilient member is axially compressed and radially expanded outwardly beyond the side peripheries of the first and second connector bodies.
This first embodiment of the connector pin assembly is illustratively utilized in conjunction with an overall wear member/adapter assembly in which the adapter nose opening has an annular interior side surface recess therein. With the connector pin resilient structure in its relaxed state, the connector pin assembly is axially inserted into the substantially aligned wear member and adapter nose opening until the resilient structure is generally aligned with the annular nose opening recess. Then, using outer end drive socket openings in the connector body members, the body members are threadingly advanced toward one another to axially compress and radially expand the resilient structure, thereby causing it to radially expand into the annular nose opening recess and come into forcible contact with its side surface.
This captively retains the inserted connector pin assembly within the adapter nose and wear member openings via both a frictional engagement between a side surface portion of the adapter nose opening and a mechanical interlock between the radially expanded resilient structure and the nose opening annular recess that receives it. The interengagement of the radially expanded resilient structure and the adapter nose resiliently mounts the connector pin in the adapter nose and wear member openings and resiliently resists axial operating loads imposed on the inserted connector pin assembly. Opposite end portions of the inserted connector pin assembly are received in the wear member openings and block the wear member against removal from the adapter nose which its socket receives.
While the interior of the adapter nose opening is preferably provided with the described annular side surface recess to radially receive the radially expanded resilient structure, this recess may be eliminated, if desired, so that the radially expanded resilient structure removably holds the inserted connector pin assembly in place solely by means of the frictional interengagement between the radially expanded resilient structure and a facing interior side surface portion of the adapter nose opening.
In a second version of the overall wear member/adapter assembly, an annular projection is formed within the adapter nose opening and has oppositely facing annular ledge surfaces thereon. A second embodiment of the connector pin assembly is used in this wear member/adapter assembly and incorporates therein a resilient structure that comprises a pair of annular flat resilient washers that are preferably of an elastomeric material. This connector pin assembly is operatively inserted into the substantially aligned wear member and adapter nose openings by inserting the first and second connector body portions inwardly through opposite ends of the aligned wear member/adapter nose openings in a manner such that the reduced diameter externally threaded portion passes through the interior adapter nose opening projection, with the resilient washers being interposed between the opposite annular ledge surfaces and the facing inner ends of the first and second connector body portions.
When the first and second connector body portions are threadingly advanced axially toward one another, the body portions compress the annular resilient washers against the annular ledge surfaces to thereby resiliently mount the inserted connector pin assembly within the substantially aligned wear member and adapter nose openings. Opposite ends of the inserted connector pin assembly are received in the wear member openings to block removal of the wear member from the adapter nose.
Neither representative embodiment of the connector pin assembly needs to be forcibly driven into the substantially aligned wear member and adapter nose openings to operatively install the connector pin assemblyxe2x80x94it is simply inserted into such openings and then threadingly tightened to operatively deform its resilient section.